Chemotherapy based on administration of carcinostatic agents is usually taken against malignant tumors which cannot be removed by ablation. Since general administration gives significant side-effects, strict limits must be imposed to the amount of medicament administered and the administration period, making it difficult to establish an effective concentration of the medicament in the tumor tissue.
To compensate for such a drawback of the chemotherapy using carcinostatic agents, intraarterial transfusion of carcinostatic agents is often employed as a therapy for allowing the medicaments to act on tumor sites at as high concentrations as possible.
One of the intraarterial transfusion therapies is an embolic chemotherapy using a balloon catheter (Cancer and Chemotherapy, Vol. 11, No. 4, pages 806-813, 1984).
This therapy involves inserting a balloon catheter through the femoral artery with the aid of an introducer, adjusting the expansion and contraction of the balloon under X-ray fluoroscopic observation, allowing the distal end of the balloon catheter to be carried by the blood flow to a destined site (an upstream position in the artery leading to the tumor site), then causing the balloon to expand to shut off the blood flow, and thereafter admitting a carcinostatic agent to the destined site through a lumen in the balloon catheter.
According to this technique, once the blood flow in the artery associated with a cancer carrying organ is temporarily shut off, the medicament is admitted to the distal side. Thus the medicament advantageously reaches the tumor at a high concentration without being diluted with blood and stays thereat for an extended period, achieving an enhanced curing effect.
However, this technique has the following drawbacks.
(1) It requires a skill to insert the balloon catheter to the destined site.
(2) Since the balloon catheter is percutaneously inserted, prolonged indwelling would increase the risk of infection.
(3) Although administration of medicament to the tumor is repeatedly carried out over a long period of time, the balloon catheter should be inserted and withdrawn every time when treatment is done in order to avoid potential infection, imposing an increased burden to the patient.
(4) Since angiography is sometimes required to evaluate the curing effect, a catheter must be additionally inserted for admitting a radiopaque agent.